Lock anti-pick device

ABSTRACT

An anti-pick device for a lock is described in which a housing is mounted over the key slot entrance in the lock and a key holder is mounted slidably in the housing for movement along a path aligned with the key slot. A recess is provided in the key holder extending transversely of the path of movement of the key holder for receiving a key and supporting the key in alignment with the key slot.

United States Patent 1191 UNITED STATES PATENTS Mcllvenny Wiczer Oct. 16, 1973 [54] 'LOCK ANTI-PICK DEVICE 3,343,306 911967 Hall 70/423 [76] Inventor: Max Wiczer, 9122 Kedvale,

Skokie, Ill. Primary Examiner-Robert L. Wolfe U s An anti-pick device for a lock is described in a [51] Eosb 17/14 housing is mounted over the key slot entrance in the [58] h 455 416 lock and a key holder is mounted slidably in the housing for movement along a path aligned with the key slot. A recess is provided in the key holder extending [56] References Cited transversely of the path of movement of the key holder for receiving a key and supporting the key in alignment with the key slot.

13 Claims, 9 Drawing Figures PAIENIED BH 3.765.199

" snmzur 3.

PATENTEDUCT 16 1973 3,765,199

' SHEET 3!]? 3 LOCK ANTI-PICK DEVICE This invention relates generally to locking devices and, more particularly, to an anti-pick device for a lock having a key slot.

A common locking device in general use comprises a front flange, an elongated threaded body extending behind the flange, and a cylinder extending from the flange, within the body. A key slot in the lock provides access to suitable internal devices which are operated by a key inserted in the slot. This enables one to turn the cylinder and operate a cam or other suitable device actuated by turning the cylinder. Typically, the flange portion of the lock is the only portion thereof which is mounted externally of the panel in which the lock is mounted, and a retainer nut is utilized threaded on the threaded body of the lock to secure the lock in place in the panel. The panel is thereby clamped between the nut and the front flange of the lock.

Various techniques have been devised by nefarious individuals within society for opening such locks without the necessity of employing'a key. Such techniques include picking, drilling, punching, and pulling the cylinder out of the lock.

In order to frustrate the activities of such persons employing the aforementioned techniques, various devices have been devised. Typically these prior art devices have not afforded as thorough protection against illegal tampering as might be desired. Moreover, such prior art devices have often been difficult to install, expensive to construct, and have sometimes required modification of the lock itself.

It is an object of the present invention to provide an improved anti-pick device for a lock having a key slot.

Another object of the invention is to provide an antipick device for a lock which prevents a direct line of sight access to the key slot.-

Another object of the invention is to provide an antipick device for a lock which provides a means of protection for the lock against picking, drilling, punching, and cylinder pulling.

Various other objects of the invention in addition to those set forth above will become apparent to those skilled in the art from the following description, taken in connection with the accompanying drawings,

wherein: I

FIG. 1 is an exploded perspective view of a device constructed in accordance with the invention;

FIG. 2 is a full cross sectional view of the device of FIG. 1, shown installed with a lock in a panel;

FIG. 3 is a view similar to FIG. 2 illustrating the position of the device of the invention when a key is inserted in the lock;

FIG. 4 is a full cross sectional view of an alternative embodiment of the invention in the installed position;

FIG. 5 is a cross sectional view of a further alternative embodiment of the invention in the installed position;

FIG. 6 is a partial sectional view taken along lines 6-6 of FIG. 5 in the direction of the arrows;

FIG. 7 is an elevational view of a specially designed key which may be advantageously used in conjunction with the device of the invention;

FIG. 8 is an end view of an alternative key holder construction which may be employed in the device of the invention for use with the key of FIG. 7; and

FIG. 9 is a sectional view of the key holder taken along line 9-9 of FIG. 8 in the direction of the arrows.

Very generally, the anti-pick device of the invention comprises a security housing ll adapted for mounting about the entrance to the slot 12 of a lock 13. A key holder 14 is mounted slidably in relation to the housing for linear movement along a path aligned with the key slot. The key holder has a recess 15 therein for receiving a key 16 and supporting the key in alignment with the key slot. The recess extends transversely of the path of movement of the key holder.

Referring now more particularly to FIGS. 1 and 2, the device of the invention in accordance with the illustrated embodiment may be more readily understood. The lock itself has a front flange 21 and a generally cylindrical body extending from behind the flange. Opposite sides of the body 23 are provided with flats 25 thereon to prevent the lock from turning in the hole in the panel in which the lock is mounted. The hole in the panel in which the lock is mounted is provided with a correspondingly out-of-round opening to mate with the flats and thus prevent rotation.

The lock 13 may be constructed internally of any suitable design, and in the illustrated embodiment, the lock 13 is provided with an internal cylinder, not shown, which, when turned, rotates a generally square stud 27 mounted at the back end of the lock. As shown in FIG. 2, the stud 27 may pass through a correspondingly shaped hole in a lock cam 29, and may be secured therein by means of a suitable bolt 31.

As is known in the art, the lock 13 is provided with a key slot 12 therein into which a key 16 may be inserted. When the key is of the proper configuration, the internal cylinder, not shown, in the lock may be rotated, to thus rotate the stud 27 and hence move the lock cam 2Q appropriately. The lock cam 29 may bear against any suitable block, panel, or latch plate, to provide locking action, as is known in the art.

The housing or body 11 is generally cylindrical in shape, having outer and inner cylindrical surfaces. An annular recess is provided at one end of the housing 11, thus providing an enlarging step in the internal diameter of the body 11. As may be seen in FIG. 2, the opposite end of the housing or body 11 is provided with an annular flange 37 which extends inwardly.

An outer retaining ring All is provided having an outer diameter matching the diameter of the recess 35 so that the outer retaining ring 41 will fit in the recess 35 as shown in FIG. 2. A pair of holes all are provided in the outer retaining ring 41 which are in alignment with a pair of threaded holes 45 in the housing II at the bottom of the recess 35. In this matter, the outer retaining ring may be secured in the recess 35 by means of screws 47 (FIG. 2).

As may be seen in FIG. 2, the outer retaining ring 41 is provided with an annular recess 51 therein, the diameter of which is equal to the inner diameter of the housing 11. An inner retaining ring 53 is provided with an outwardly projecting flange 55 which fits within the annular recess 51 in the outer retaining ring 41.

The panel 57 in which the lock 13 is mounted may be any wall, door or similar structure. The inner diameter of the inner retaining ring 53 is made such as to be less than the outer diameter of the flange 21 on the lock 13. In this manner, the inner retaining ring 53 may be clamped against the panel 57 between the flange 21 and a lock retainer nut 59 threaded on the threaded body 23 of the lock 113. The flange 55 of the inner retaining ring retains the outer retaining ring 41 between it and the panel 57 and thereby secures the housing 11 over the key slot entrance 12 of the lock 13.

As previously mentioned, the key holder 14 is mounted slidably in the housing 11 for movement along a path aligned with the key slot 12. To this end, the key holder 14, which in the illustrated embodiment is generally cylindrical, is provided with an annular flange 61 which projects radially outward at one end of the key holder and which has an outer surface of a diameter equal to and mating with the inner surface of the housing 11. The outer diameter of the cylindrical key holder 14 is slightly less than the inner diameter of the inwardly projecting flange 37 on the housing 11. Thus, the key holder 14 is mounted in and guided within the housing 11, but may not be pulled out of the housing.

The key holder 14 is provided with a recess therein for receiving the key 33 for supporting same in alignment with the key slot. In the illustrated embodiment, this recess comprises a slot which extends along the axis of the cylindrical key holder to the end thereof disposed interiorly of the housing 1 1. The slot does not extend to the opposite end of the key holder 14, and thereby leaves a wall 65 which extends transversely to the path of movement of the key holder 14.

In the illustrated embodiment, a small hole 67 is provided at the base of the recess 15, and the key is provided with a stud 69 thereon which mates within the hole to aid in retaining the key in position with respect to the key holder 14. Also in the illustrated embodiment the key 16 is provided with an L-shaped extension 71 thereon to facilitate inserting the key into and removing the key from the recess 15 in the key holder 14. Since the key holder 14 is free to rotate with respect to the key slot 12 in the lock 13, and since the breadth of the recess 15 is selected to properly align the key 16 with the key slot entrance, the key holder may be moved linearly to cause the key to enter the key slot, and may then be turned to cause the key to turn the internal cylinder within the lock 13 and open the lock. FIG. 3 shows the key inserted in the lock with the key holder in its innermost position.

In assembling the device of the invention, the key holder is inserted into the body 11 so that the barrel of the key holder protrudes through the opening provided by the annular flange 37. The flange 61 prevents the key holder from passing through the opening in the housing 11. The lock 13 is then inserted through the hole in the inner retaining ring and the inner retaining ring is then placed into the annular recess 51 in the outer retaining ring. The outer retaining ring is then placed into the annular recess 15 in the housing 11 and secured therein by the screws 47. The lock is then inserted into the hole in the panel 57 and secured therein by the retainer nut 59. The housing assembly is thus secured over the entrance to the slot 12.

In operating the device of the invention, the key holder 14 is pulled out from the housing 11 as far as possible, i.e., the position shown in FIG. 2. The key is then inserted in the recess 15 with the stud 69 projecting downwardly into the hole 67 at the bottom of the slot. The key holder 14, with the key placed therein, is then pushed inwardly. While maintaining pressure on the key holder 14, the key holder is also rotated until the key 16 finds and enters the keyway or slot 12 of the lock 13. The key is then pushed into the lock by further movement of the key holder and the key holder is then turned to operate the lock.

Because the housing 11 surrounds the entrance to the slot 12 in the lock 13, and because the key holder 14 fills up the opening in the housing 11, the only external access to the lock is through the recess 15. Since the recess 15 does not extend through the entire length of the key holder 14, but rather extends transversely of the path of movement of the key holder, a direct line of sight into the lock is prevented. Accordingly, a conventional lock picking tool cannot be used to pick the lock, and any picking attempt by the utilization of other tools must be blind. The external parts of the device of the invention are preferably hardened to resist cutting and drilling. By making the inner diameters of the outer retainer ring 41 larger than the outer diameters of the inner retainer ring 53, any torque applied to the housing merely rotates the housing about the lock. Accordingly, the lock cannot be removed by forcing it or unthreading it from the retainer nut 59.

An alternative embodiment of the invention is illuwtrated in FIG. 4. In FIG. 4, those elements of the device and associated structure which have function and design similar to the elements of the embodiment of FIGS. 1 to 3 have been given identical reference numerals, preceded by a 1. As may be seen in the embodiment of FIG. 4, the housing 111 is secured directly to the panel 157 by means of screw 147 which enter directly into the housing. This design eliminates the need for the inner and outer retaining rings because the housing is secured to the panel independently of the lock.

Additionally, an optional blocking means 148 is schematically illustrated in FIG. 4 for normally covering the key slot of lock 113, but being movable relative to the key slot to permit access thereto for insertion of the key 116. This provides an additional measure of security against blind picking of the lock through the use of perhaps a more sophisticated or specially designed picking tool. Blocking means 148 may comprise any suitable mechanical form, such as a parting curtain" having a pair of planar members which separate through the urging or contact with the inner end of the key as the key is axially moved toward the key slot. This will be described in greater detail in connection with FIGS. 5 and 6.

Alternatively, the blocking means 148 may comprise a pivotable vane or shutter which moves to its access position in response to the movement of the key holder 1 14 relative to the key slot by any suitable camming arrangement or linkage between the key holder and the shutter as indicated by broken line 150. In this embodiment, axial movement of the key holder to its closed or key engaged position (as shown, for example, in FIG. 3) is required to move the blocking means 148 to its open or access position. Any mechanism of suitable size for translating the linear movement of the key holder to angular movement of the shutter may be employed.

As a further alternative, the lock itself may be mounted to a panel, housing or bracket which is behind a second panel, serving as the main panel or door. The second panel may have a hold therein for accommodating and guiding the key holder. Accordingly, in this situation the second panel comprises the security housing, and the need for a closed cylindrical type of security housing as has been hereinbefore described may be eliminated.

More particularly, reference is made to FIG. 5 which shows a further alternative embodiment, with those elements of the device and associated structure having function and design similar to the elements of the embodiment of FIGS. 1 and 3 given like reference numerals, preceded by a 2. As can be seen, the panel 257, together with the housing body 211, forms the security housing, since the panel 257 blocks access to the key slot of the lock 213 except through the opening 252 in the panel. The body 211 serves to support the lock 213 in fixed mounted relation to the panel and to the opening 252 therein. The body 211 may be fastened to the back or interior side of the panel 257 by means of screws 247 inserted through ears 254 formed integrally with the body. As shown, th key holder 214 has a flange 261 which nests within a counterbore at the back of the panel or door 257 when the key holder is in its open or extended position.

Blocking means 248 may be optionally included, and is shown to comprise a pair of separable metal vanes 258a and 258b (FIG. 6) which are respectively pivot mounted at 262a and 262!) for'angular motion as shown by the arrows. Each point is located so that the center of mass of the vanes causes them to normally swing together in the closed position shown in FIG. 6 under the force of gravity. An inward bevel may beprovided along the respective inner edges 264a and 264k of the vanes so that they will readily separate when contacted by the inner end of the key 216 as it is urged forwardly toward the key slot. The parting line of the vanes, being aligned with the key slot, will open and permit entry of the key when the key holder 214 has been rotated to the proper angular orientation.

Of course, other mechanisms, employing springs, etc. may be utilized for the blocking means of the embodiment of FIG. 5, as well as of the embodiment of FIG. 4. Also, any such means may be employed with the embodiment of FIGS. 1 to 3, if desired. It is understood that the key slot may be of a shape other than flat or straight such as circular or other special configurations.

FIG. 7 shows an alternative key design-which may be used with the modified key holder construction of FIGS.'8and 9. The key 16' has a straight tumbler engaging portion 302 along an axis 304 defined thereby for insertion into a key slot of a lock, aspreviously described. A tang or gripping portion 306 is joined to the straight key portion 302 by a stem 308 having a curved bearing surface 310 extending from one side ofthe axis 304 to the other. a

The key holder 14' is similar to that hereinbefore described, except that the recess 63' has a key supporting wall 312 forming a curved surface extending from an external point 314 furthest from the key slot to an external point 316 on the face of the key holder closest to the key slot, and from one side of its longitudinal axis 318 to the other. The curvature of the supporting wall 312 mates with the complementary bearing surface 310 of the key 16', and the key nests securely within the recess 63' in proper alignment with the key slot for easy insertion and removal.

With the key placed within the key holder, the tang 306 hooks over the rearward end 320 of the key holder so that the straight surface 322 abuts flush against end 320. A hole 324 is provided within the tang 306 for key chain convenience. Of course, portions of the mating bearing and supporting surfaces may be straight or approximately straight in some circumstances, but generally less advantageously.

It may therefore be seen that the invention provides an improved anti-pick device for a lock having a key slot. The device provides a means of protection for the lock against picking, drilling, punching, cylinder pulling, and many other types of nefarious activities. The device of the invention is relatively simple of construction, is easily installed, and represents a significant improvement over the known prior art.

Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art, from the foregoing de-- scription and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims.

What is claimed is:

1. An anti-pick device for a lock having a key slot, comprising, a housing adapted for mounting surrounding the key slot entrance, said housing having an opening therein aligned with the key slot, a key holder mounted slidably in relation to said housing for movement along a path aligned with the key slot, said key holder generally filling said opening in said housing, and said means for preventing withdrawal of said key holder from said housing, said key holder having a recess therein for receiving a key and supporting same in alignment with the key slot, said recess extending trans versely of the path of movement of said key holder and extending axially to open in alignment with the key slot only within said housing.

2. A device according to claim 1 wherein said key holder is also mounted for rotation in relation to said housing for movement about an axis aligned with the key slot.

3. A device according to claim 1 wherein said housing is generally of cylindrical interior cross section, wherein said key holder has a generally cylindrical surface mating with the interior of said housing, and wherein said recess comprises a slot extending along the axis of said key holder and opening out of an end thereof within said housing.

4. A device according to claim 1 including mounting means for mounting said housing to a panel in which the lock is supported.

5. A device according to claim 4 wherein said mounting means comprises at least one annular retaining ring secured to said housing interiorly thereof.

6. In combination with a lock having a key slot for mounting in fixed relation to a panel, an anti-pick device comprising, a housing mounted to the panel surrounding the entrance to said key slot, said housing having an opening therein aligned with the key slot, a

7 key holder mountedslidably in-relation to said housing for movement along a path aligned with said key slot, said key holder generally filling said opening in said housing, and means for preventing withdrawal of said key holder from said housing, said key holder having a recess therein for receiving a key and supporting same in alignment with said key slot, said recess extending transversely of the path of movement of said key holder and extending axially to open in alignment with the'key slot only within said housing.

7. A combination according to claim 6 including means for mounting said housing to said panel, said mounting means comprising an outer retainer ring secured to said housing, an inner retainer ring secured to said lock and said panel, said inner retainer ring and said outer retainer ring having inter-engaging surfaces thereon permitting rotary movement of said retainer rings with respect to each other.

8. The combination as defined in claim 6 wherein said housing is secured to the panel independently of said lock.

9. The combination as defined in claim 6 wherein said lock is mounted in said housing with the key slot in communication with the interior thereof, and the housing is mounted to the panel, said panel having an opening therein for accommodating said key holder.

10. The combination as defined in claim 6 wherein said device comprises means for normally covering the key slot, but being movable relative thereto to permit access to the key slot for insertion of a key.

11. The combination as defined in claim 10 wherein said means is movable to its access position through contact with the inner end of the key as the key is being axially moved toward the key slot.

12. The combination as defined in claim 10 wherein said means is movable to its access position in response to the movement of said key holder relative to the key slot.

13. The combination as claimed in claim 6 wherein the recess of said key holder has a key supporting wall forming a generally curved surface extending from an external point furthest from said key slot to an external point on the face of the key holder closest to said key slot and said curved surface mates with a complementary surface on the key to achieve said alignment. 

1. An anti-pick device for a lock having a key slot, comprising, a housing adapted for mounting surrounding the key slot entrance, said housing having an opening therein aligned with the key slot, a key holder mounted slidably in relation to said housing for movement along a path aligned with the key slot, said key holder generally filling said opening in said housing, and said means for preventing withdrawal of said key holder from said housing, said key holder having a recess therein for receiving a key and supporting same in alignment with the key slot, said recess extending transversely of the path of movement of said key holder and extending axially to open in alignment with the key slot only within said housing.
 2. A device according to claim 1 wherein said key holder is also mounted for rotation in relation to said housing for movement about an axis aLigned with the key slot.
 3. A device according to claim 1 wherein said housing is generally of cylindrical interior cross section, wherein said key holder has a generally cylindrical surface mating with the interior of said housing, and wherein said recess comprises a slot extending along the axis of said key holder and opening out of an end thereof within said housing.
 4. A device according to claim 1 including mounting means for mounting said housing to a panel in which the lock is supported.
 5. A device according to claim 4 wherein said mounting means comprises at least one annular retaining ring secured to said housing interiorly thereof.
 6. In combination with a lock having a key slot for mounting in fixed relation to a panel, an anti-pick device comprising, a housing mounted to the panel surrounding the entrance to said key slot, said housing having an opening therein aligned with the key slot, a key holder mounted slidably in relation to said housing for movement along a path aligned with said key slot, said key holder generally filling said opening in said housing, and means for preventing withdrawal of said key holder from said housing, said key holder having a recess therein for receiving a key and supporting same in alignment with said key slot, said recess extending transversely of the path of movement of said key holder and extending axially to open in alignment with the key slot only within said housing.
 7. A combination according to claim 6 including means for mounting said housing to said panel, said mounting means comprising an outer retainer ring secured to said housing, an inner retainer ring secured to said lock and said panel, said inner retainer ring and said outer retainer ring having inter-engaging surfaces thereon permitting rotary movement of said retainer rings with respect to each other.
 8. The combination as defined in claim 6 wherein said housing is secured to the panel independently of said lock.
 9. The combination as defined in claim 6 wherein said lock is mounted in said housing with the key slot in communication with the interior thereof, and the housing is mounted to the panel, said panel having an opening therein for accommodating said key holder.
 10. The combination as defined in claim 6 wherein said device comprises means for normally covering the key slot, but being movable relative thereto to permit access to the key slot for insertion of a key.
 11. The combination as defined in claim 10 wherein said means is movable to its access position through contact with the inner end of the key as the key is being axially moved toward the key slot.
 12. The combination as defined in claim 10 wherein said means is movable to its access position in response to the movement of said key holder relative to the key slot.
 13. The combination as defined in claim 6 wherein the recess of said key holder has a key supporting wall forming a generally curved surface extending from an external point furthest from said key slot to an external point on the face of the key holder closest to said key slot and said curved surface mates with a complementary surface on the key to achieve said alignment. 